JP4883330B2 - Variable valve operating device for internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine that uses a cam phase changing mechanism to change the phase of one cam of a pair of cams that drive a pair of intake valves or a pair of exhaust valves relative to the other cam.

In a reciprocating engine (internal combustion engine) mounted on an automobile, a variable valve gear is being mounted on a cylinder head in order to prevent engine exhaust gas and improve pumping loss.
The variable valve operating system has a structure in which a phase between the valves of a multi-valve (a pair of intake valves and a pair of exhaust valves) widely used in an engine is varied to change a period during which the multi-valve is open. . For example, among a pair of cams that drive a pair of intake valves or a pair of exhaust valves, a device that varies the phase of the other cam with respect to one cam has been proposed.

  This variable valve operating device is difficult to realize with a camshaft in which a cam is integrally formed with a normal shaft member. For this reason, the variable valve device uses a camshaft having an assembly cam structure in which a separate cam member (component) is rotatably assembled to the shaft member, thereby realizing a variable phase between the valves. For example, as disclosed in Patent Documents 1 and 2, the first cam on the reference side is fixed on the outside of the shaft member driven by the crank output in accordance with the arrangement of the pair of intake valves or the pair of exhaust valves. A structure in which a second cam having the same cam width on a pair of movable sides is fitted so as to be displaceable in the circumferential direction, and the phase of the second cam is changed on the basis of the first cam by a cam phase changing mechanism such as a movable vane mechanism. Used.

  Of course, as with other engines, the cam displacement of the first cam and the second cam is transmitted to each valve via a follower member of a tappet member (or a rocker member or the like), and a pair of intake valves or a pair of exhaust valves. The open period of is greatly changed.

JP 2009-144521 A JP 2009-144522 A

  In a general camshaft in which the cam is integrally fixed to the shaft, when the cam journal is provided between the first cam and the second cam, the first cam and the second cam have substantially the same valve lift and timing. Since the valve lift load acts equally on the cam journal width, misalignment does not increase. However, when the phase of the first cam and the second cam is shifted by the variable valve operating device, the valve lift load acts on the time difference between before and after in the cam journal width direction, resulting in misalignment. For this reason, the cam surfaces of the first cam and the second cam have a reduced contact area with the cam contact portion of the tappet or the rocker, resulting in a high load and an inability to maintain a good lubrication state. Causes uneven wear.

  Further, the second cam used in the variable valve operating device is rotatable in the circumferential direction of the shaft member, unlike a structure integrally formed with a normal shaft member or a first cam fixed to the shaft member. For this reason, there is a minute clearance necessary to rotate the shaft member. Since this clearance promotes misalignment of the second cam, it causes a further increase in friction with the cam contact portions of the tappet and the rocker and causes uneven wear. In addition, the misalignment causes instability of the clearance, the offset load acting on the sliding surface of the second cam and the shaft member also increases, and the responsiveness is deteriorated due to the increased friction and wear of the part is also generated.

When such a thing occurs, the variable valve mechanism varies in variable performance. For this reason, it is conceivable to employ misalignment processing, improve assembly accuracy, and use highly wear-resistant materials and surface treatment that can withstand misalignment, but both are expensive and require alternative technologies. .
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a variable valve operating apparatus for an internal combustion engine that has a simple structure and can improve resistance to misalignment of a cam that performs phase change.

In order to achieve the above object, the invention according to claim 1 uses the cam width of the second cam provided on the outside of the shaft member so as to be displaceable in the circumferential direction in the variable valve operating apparatus as a reference for the second cam. The cam width is larger than the cam width of the cam surface of one cam.
The invention according to claim 2 is configured such that the shaft member is configured such that the inner cam shaft is rotatably accommodated in an outer cam shaft formed of a pipe member, and the first cam is provided on the outer peripheral portion of the outer cam shaft, The second cam is provided so as to be rotatable around the axis of the outer cam shaft, and the phase of the second cam can be changed based on the first cam by relative displacement between the outer cam shaft and the inner cam shaft. did.

The invention according to claim 3 is a camshaft applied to an internal combustion engine of the same model as the internal combustion engine, wherein the camshaft includes a cam integral with a shaft member. The cam width of the first cam is larger than the width.

According to the first aspect of the present invention, the contact area with the cam contact portion of the tappet or the rocker due to misalignment of the cam surfaces of the first cam and the second cam is maintained, and a good lubrication state is maintained. Increase in friction and uneven wear are suppressed, and the maximum value of the uneven load acting on the sliding surfaces of the second cam and the shaft member due to misalignment is reduced.
Therefore, with a simple structure, it is possible to increase the tolerance against misalignment of the cam that performs phase change.

According to the invention of claim 2, since the outer cam shaft is formed of a pipe member having low bending rigidity, the force applied from the second cam to the outer cam shaft using the second cam having a large cam width dimension. Can be distributed.
According to the invention of claim 3, each of the first cam and the second cam has an optimum cam width, and can effectively cope with misalignment associated with variable splitting, and is effective in deteriorating responsiveness and uneven wear due to increased friction. Can be suppressed.

1 is a plan view of an internal combustion engine equipped with a variable valve gear according to a first embodiment of the present invention. Sectional drawing of the variable valve apparatus which follows the II line | wire in FIG. Sectional drawing which shows the cam shaft in which the cam was integrally formed. The disassembled perspective view which shows the structure of each part of a variable valve apparatus. The diagram which shows the variable characteristic of a variable valve apparatus. The figure for demonstrating the difference in the contact state of the cam and tappet which the change of a cam width brings. The top view which shows the principal part of the 2nd Embodiment of this invention.

Hereinafter, the present invention will be described based on a first embodiment shown in FIGS.
FIG. 1 shows a plan view of an internal combustion engine, for example, a multi-cylinder reciprocating engine (hereinafter simply referred to as an engine), and FIG. 2 shows a cross section taken along line I-I in FIG. The cylinder block 2 is a cylinder head mounted on the head of the cylinder block 1.

Among these, the cylinder block 1 is formed with a plurality of cylinders 3 (only some cylinders are shown) along the longitudinal direction of the engine as shown in FIGS. In each cylinder 3, each piston 4 separated from a crankshaft (not shown) via a connecting rod (not shown) is housed so as to be able to reciprocate.
A combustion chamber 5 is formed on the lower surface of the cylinder head 2 corresponding to each cylinder 3. Each combustion chamber 5 has a pair of intake ports 7 (two) for performing intake and a pair of exhaust ports (not shown) for performing exhaust. Each intake port 7 is provided with a pair of intake valves 10 (two) each having a bottomed cylindrical tappet 9 (driven member) attached to the stem end. A spherical crowning (cam contact surface) formed on the top surface 9 a of each tappet 9 faces the upper portion of the cylinder head 2. Each exhaust port (not shown) is similarly provided with a pair of exhaust valves (both not shown) with tappets. Similarly, the valve base end faces the upper part of the cylinder head 2. The intake port 7 and the exhaust port (not shown) are opened and closed by the intake valve 10 and the exhaust valve (not shown). Each combustion chamber 5 is provided with a spark plug (not shown).

  In addition, on the left and right of the upper part of the cylinder head 2, there are provided an intake side valve operating device 6a driven by a crankshaft shaft output, and an exhaust side valve operating device 6b. (4 cycles of intake stroke, compression stroke, expansion stroke, and exhaust stroke) are repeatedly performed. Of these valve gears 6a and 6b, the exhaust-side valve gear 6b has a structure using a normal camshaft 13 shown in FIG. 3, for example. Specifically, a camshaft formed integrally with an exhaust cam, specifically, a camshaft 13 formed by machining the exhaust cams 12 for a plurality of cylinders together with a shaft 13a (shaft member) is used. This camshaft 13 is assembled so as to be rotatable in the direction in which the cylinders 3 are arranged, and the cam surface of each exhaust cam 12 is brought into contact with the crowning (not shown) of the top surface of the tappet. Thus, the cam displacement of each exhaust cam 12 is transmitted to an exhaust valve (not shown).

Unlike the exhaust-side camshaft 13, the intake-side valve gear 6a includes a camshaft constituted by assembling separate parts as shown in FIG. It is used. The camshaft 14 is used to form a split type variable valve operating device 15 as shown in FIG.
That is, the shaft member of the camshaft 14 is, for example, an inner camshaft 17b formed of a solid shaft member serving as a control member in an outer camshaft 17a formed of a pipe member as shown in FIGS. Is formed by a double shaft 17 (corresponding to the shaft member of the present application). The double shaft 17 is also arranged along the direction in which the cylinders 3 are arranged, like the camshaft 13 on the exhaust side. One end portion (one side) of the double shaft 17, that is, one end portion of the outer cam shaft 17 a is connected to one end of the cylinder head 2 via a bracket 37 attached to the end of the outer cam shaft 17 a. It is rotatably supported by a bearing portion 18a installed at the end (one side). The intermediate portion of the outer camshaft 17a is rotatably supported by an intermediate bearing portion 18b installed between the tappets 9,9. Thus, both shafts 17a, 17b can be rotated about the same axis. The outer camshaft 17a and the inner camshaft 17b can be relatively displaced by a clearance.

The outer cam shaft 17a is provided with a pair (two) of intake cams 19 corresponding to the pair of intake valves 10 for each cylinder. Each intake cam 19 is configured by combining a fixed cam 20 (corresponding to the first cam of the present application) that defines a reference phase and a cam lobe 22 (corresponding to the second cam of the present application) on the movable side.
That is, the fixed cam 20 serving as the reference side is provided in an outer peripheral portion corresponding to a tappet on one side of the outer cam shaft 17a, for example, the tappet 9 on the left side. Specifically, the fixed cam 20 is formed of a plate cam, and is fixed by being fitted to the outside of the outer cam shaft 17a, specifically, fixed by press-fitting. The cam surface 20a formed on the outer peripheral surface of the fixed cam 20 abuts on the crowned top portion 9a of the left tappet 9, and the cam displacement of the fixed cam 20 is transmitted to the left intake valve 10b.

  The cam lobe 22 has a cam nose 22a formed by a plate cam. A portion for ensuring stability, that is, a hollow boss portion 22b is combined with the cam nose portion 22a to constitute the entire cam lobe. The cam crest portion 22a and the boss portion 22b are fitted on the outer side of the outer cam shaft 17a so as to be freely rotatable (displaceable) in the circumferential direction, and the cam crest portion 22a is disposed immediately above the remaining right tappet 9. A cam surface 22c formed on the outer peripheral surface of the cam peak portion 22a abuts on the crowned top portion 9a of the right tappet 9, and the cam displacement of the cam peak portion 22a is transmitted to the right intake valve 10a.

  The boss portion 22b and the inner camshaft 17b are connected while allowing relative displacement of the inner and outer shafts 17a and 17b by a connecting member, for example, a press-fit pin 24 that is press-fitted so as to penetrate the diameter direction of the double shaft 17. ing. By this connection, the cam crest 22 a (cam lobe 22) can be displaced relative to the fixed cam 20. That is, as shown in FIG. 4, holes that allow the press-fit pins 24 to escape, for example, a pair of long holes 26 extending in the retarded direction, are formed in the peripheral wall portions of the outer cam shaft 17 a through which the press-fit pins 24 pass. The inner cam shaft 17b can be displaced relative to the outer cam shaft 17a. Thus, the cam crest portion 22a can be varied until it is largely retarded from the phase of the reference fixed cam 20. In FIG. 4, 14a indicates a press-fitting hole formed in the inner cam shaft 17b, and 14b indicates a press-fitting hole formed in the peripheral wall portion of the boss portion 22b.

A cam phase changing mechanism 25 for relatively displacing the inner and outer shafts 17a and 17b is attached to one end of the double shaft 17 so that the cam phase of the cam lobe 22 can be changed based on the fixed cam 20. The apparatus 15 is comprised.
For example, as shown in FIGS. 2 and 4, the cam phase changing mechanism 25 includes a plurality of vanes radially from the outer peripheral portion of the shaft portion 32 in a cylindrical housing 31 having a plurality of retarding chambers 30 along the circumferential direction. A rotating vane structure is used in which the vane portion 34 projecting from 33 is rotatably accommodated and each vane 33 partitions the inside of each retarded angle chamber 30. A timing sprocket 39 is provided on the outer peripheral portion of the housing 31. The sprocket 39 is connected via a timing chain 40 to a crankshaft (not shown) together with a timing sprocket 13a attached to the end of the camshaft 13 on the exhaust side. The housing 31 is connected to a bracket 37 (shown in FIG. 2) at the end of the outer cam shaft 17a by a fixing bolt 36, and the shaft portion 32 of the remaining vane portion 34 is connected to the shaft end of the inner cam shaft 17b by a fixing bolt 38. When the vane 33 is connected and rotationally displaced in the retard chamber 30, the inner cam shaft 17b is displaced relative to the outer cam shaft 17a.

  More specifically, the cam phase of the cam peak portion 22a is determined by the urging force of a return spring member 42 (shown only in FIG. 2) provided so as to pass between the housing 31 and the vane portion 34. Aligned to 20 cam phases. Each retard chamber 30 is provided with an oil control valve 44 (hereinafter referred to as OCV 44) through various oil passages 43 (only part of which are shown in FIG. 2) formed in the housing 31, the bracket 37, and the bearing portion 18a. , Connected to a hydraulic pressure supply unit 45 (for example, a device having an oil pump for supplying oil). That is, when the oil is supplied into each retarding angle chamber 30, the camshaft 14 on the intake side is split so that the cam peak portion 22a is displaced from the fixed cam 20 in the retarding direction.

  That is, the split variable will be described. The shaft output from the crankshaft is transmitted to the outer shaft 17a via the timing chain 40, the timing sprocket 39, the housing 31, and the bracket 37, and the fixed cam 20 is driven to rotate. Then, the left intake valve 10b is opened and closed. Here, when the hydraulic pressure is supplied from the OCV 44 to the advance chamber (not shown) on the opposite side of each retard chamber 30, the cam crest portion 22 a is coupled with the urging force of the return spring member 42 as shown in FIG. Since the cam phase of the fixed cam 20 is aligned as in the state A, the right intake valve 10a is opened and closed while maintaining the same phase as that of the left fixed cam 20. When the hydraulic pressure of the hydraulic pressure supply unit 45 is supplied into the retard chamber 30 through the OCV 44, the vane 33 is displaced from the initial position to the retard side in the retard chamber 30 according to the hydraulic pressure output. At this time, for example, when the vane 33 is displaced halfway in the retard chamber 30 by hydraulic pressure output control, the inner cam shaft 17b is displaced in the retard direction to the midway position. The displacement at this time is transmitted to the cam lobe 22 through the press-fit pin 24, and the cam peak portion 22a is displaced in the retarding direction. Then, as shown in the state B in FIG. 5, the open / close timing of the left intake valve 10b as a reference remains unchanged, and only the open / close timing of the right intake valve 10a changes. That is, the right intake valve 10a is opened / closed according to the cam profile of the cam peak portion 22a from the middle of the opening / closing period of the left intake valve 10b. When the vane 33 is displaced to the most retarded position by hydraulic output control, the opening and closing timing of the left intake valve 10b remains unchanged as shown in the state C in FIG. 5, and the right intake valve 10a is left unchanged. Opens and closes at the most retarded time from the left intake valve 10b while maintaining a state in which the left intake valve 10b opens and closes. That is, the valve opening periods of the left and right intake valves 10 are varied within the range from the smallest valve opening period α to the largest valve opening period β (split variable) according to the state of the engine.

The variable valve operating device 15 that causes the cam lobe 22 to be phased with respect to the fixed cam 20 has a problem peculiar to the device 15 because the cam lobe 22 is rotatable.
That is, unlike the fixed cam 20, the cam lobe 22 assembled to the double shaft 17 is required to be able to rotate the outer peripheral surface of the outer cam shaft 17a. Therefore, the cam lobe 22 is provided between the cam lobe 22 and the outer cam shaft 17a. There is a small clearance necessary to rotate. In addition, since the clearance includes the component tolerance of the cam lobe 22 and the outer cam shaft 17a and the assembly tolerance when assembling both components, the cam crest 22a is easily displaced over a wide range, and the posture of the cam surface 22c is likely to vary ( Not constant). That is, as shown in FIG. 6A, the cam surface 22c is likely to be misaligned with respect to the center of the cam shaft.

  Further, in the state of B and C in FIG. 5, misalignment occurs because the valve lift load works with a time difference under such a situation. That is, in a general cam shaft in which the cam is integrally fixed to the shaft, when the cam journal is provided between the first cam at the fixed cam position and the second cam at the cam lobe position, the first cam and the second cam When the cams have substantially the same valve lift and timing, the valve lift load acts equally on the cam journal width, so misalignment does not increase. However, when the phase of the fixed cam 20 serving as the first cam and the cam lobe 22 serving as the second cam are shifted in the variable valve operating device 15, the valve lift load acts on the cam journal 18b in the width direction before and after the cam journal 18b in the width direction. Misalignment occurs.

  For this reason, as shown in FIG. 6 (a), when misalignment of the cam surface 22c occurs, contact between the crowned top portion 9a, which is a predetermined position of the cam contact surface of the tappet 9, and the cam width end portion is caused. May occur. In addition, the valve lift may not be performed according to the designed cam. When this occurs, as shown in FIG. 6A, the cam surface 22c has a reduced contact area with the cam contact portion of the tappet 9, resulting in a high load, and a good lubrication state cannot be maintained. This causes an increase in friction at the contact portion and uneven wear.

  Therefore, the cam surface of the cam crest 22a that changes the phase as shown in FIGS. 1, 2, and 4 is not the idea that the cam width of the fixed cam 20 and the cam crest 22a that are paired is the same. The cam width dimension of 22c was made larger than the cam width dimension b of the cam surface 20a of the fixed cam 20 to make the cam width dimension different. That is, the cam surface 22c of the cam nose 22a is formed with a larger cam width than the cam surface 20a of the fixed cam 20 (a> b).

  Then, as shown in FIG. 6B, even if misalignment occurs, contact between the crowned top surface 9a of the cam contact surface of the tappet 9 and the cam width end portion of the cam peak portion 22a can be avoided. . Thus, the contact area with the top surface 9a (cam contact portion) due to misalignment of the cam surface 22c is maintained. Thereby, the load of the contact part in the cam peak part 22a and the top surface 9a can be disperse | distributed, and a maximum load also falls. The same applies to misalignment associated with variable splitting, that is, misalignment that occurs when a valve lift load is applied with a time difference before and after the cam journal width direction.

That is, when the cam width of the cam peak portion 22a is increased, the allowable range for misalignment on the cam surface 22c of the cam peak portion 22a increases. In addition, since the stability of the cam nose 22a itself is increased, the influence of the clearance and assembly tolerance for rotating the cam nose 22a can be suppressed.
Therefore, the tolerance to the misalignment of the cam that changes the phase can be enhanced with a simple structure. Therefore, the camshaft 14 can be assembled to the cylinder head 2 in the same manner as the conventional cam (FIG. 2), and it is possible to suppress troublesome alignment work and improvement of the processing accuracy of each of the previous components (no processing accuracy is required). ). Furthermore, the maximum value of the unbalanced load acting on the sliding surfaces of the cam nose 22a (second cam) and the outer camshaft 17a (shaft member) due to misalignment is reduced, and the response and deterioration due to increased friction are also reduced. Can be suppressed. In addition, the inclination of the cam nose 22a can be suppressed by increasing the cam width dimension, so the occurrence of friction and uneven wear due to the instability of the cam nose 22a can be suppressed, and good variable performance can be secured. can do. In addition, since the valve lift as designed is obtained, there is no performance degradation or NVH deterioration. In addition, since the outer cam shaft 17a is formed of a pipe member having low bending rigidity, if the cam width of the cam peak portion 22a is increased, the force transmitted from the cam peak portion 22a to the outer cam shaft 17a is dispersed, which is good. There is also an advantage that a variable performance is maintained.

  In particular, as shown in FIG. 1, the cam width dimension b of the fixed cam 20 is a cam width dimension of a camshaft that is used in the same type of engine and has a cam integral with a shaft member, for example, the shaft 13a shown in FIG. The cam width dimension c of the cam surface of the exhaust cam 12 of the camshaft 13 having the integral exhaust cam 12 and the intake cam of the intake camshaft integrated with the intake cam used in the series of the same model engine but not variable. The cam width of the cam surface is larger (a> c, b> c), and by setting the optimum cam width for each, the influence of assembly tolerances is also exerted on the fixed cam 20 constructed by assembling separate parts. In addition to avoiding this, it can handle misalignment associated with variable splits.

Needless to say, such an effect can also be obtained when the crowning of the cam contact surface of the tappet 9 is provided on the cam surface 22c side.
FIG. 7 shows a second embodiment of the present invention.
In the present embodiment, a phase change device is provided at one end of a double shaft 17 (shaft member) in which a fixed cam 20 (first cam) and a cam lobe 22 (second cam) are assembled as in the first embodiment. 25, and not the variable valve operating device 15 that varies the phase of the cam lobe 22 with respect to the fixed cam 20, but a variable valve operating device 50 to which the function of changing the phase of the fixed cam 20 and the phase of the cam lobe 22 is added. Further, the present invention is applied.

  That is, the variable valve operating device 50 is attached to one end of the double shaft 17 (shaft member) in which the fixed cam 20 (first cam) and the cam lobe 22 (second cam) are assembled, for example, the end on the rear side of the engine. A phase change mechanism 25 (first) having the same structure as that of the first embodiment is connected, and a second phase change mechanism 51 formed of a rotating vane structure such as VVT is provided at the end on the other engine front side. In addition to the variable phase due to the relative displacement between the outer cam shaft 17a and the inner cam shaft 17b, the phase between the fixed cam 20 and the cam lobe 22 is determined by the integral rotational displacement of the outer cam shaft 17a and the inner cam shaft 17b. Is made to be integrally variable.

Even when the present invention is applied to the variable valve apparatus 50, the same effects as those of the first embodiment can be obtained. However, in FIG. 7, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
In addition, this invention is not limited to any embodiment mentioned above, You may implement variously within the range which does not deviate from the main point of this invention. For example, in the embodiment, the structure in which the valve is driven by receiving the cam displacement with the tappet has been described. You may apply. When a valve is driven by a rocker member, there is a case where a single cam contact surface is provided on the cam side of the rocker member, a bifurcated valve drive unit is provided on the valve side, and a plurality of valves are driven by one cam. In this case, the cam width dimension refers to a dimension per valve obtained by dividing the actual cam width by the number of drive valves (= actual cam shaft / number of drive valves). Of course, the present invention is not limited to the variable valve operating apparatus that relatively changes the phase of the pair of intake cams as in the above-described embodiment. You may apply to a valve apparatus. Further, the engine to be applied may be an engine having a valve operating system in which a valve driving structure is combined with a variable valve device separately using a cam shaft integrally formed with a cam.

DESCRIPTION OF SYMBOLS 10 Pair of intake valves 12 Exhaust cam 13 Exhaust side camshaft 14 Intake side camshaft 15 Variable valve gear 17 Double shaft (shaft member)
17a Outer camshaft 17b Inner camshaft 19 Intake cam 20 Fixed cam (first cam)
20a Cam surface of fixed cam 22a Cam crest (second cam)
22c Cam surface of cam crest 25 Cam phase change mechanism a Cam width of cam crest b Cam width of fixed cam

Claims (3)

In a variable valve operating apparatus for an internal combustion engine that varies a phase between a pair of intake valves provided for one cylinder or a phase between a pair of exhaust valves,
A shaft member driven by the crank output of the internal combustion engine;
A first cam provided on the outside of the shaft member and having a cam surface for driving one of the pair of intake valves or one of the pair of exhaust valves;
A second cam having a cam surface for driving the other side of the intake valve or the other side of the exhaust valve, provided on the outer side of the shaft member so as to be displaceable in the circumferential direction;
A cam phase change mechanism that changes the phase of the second cam with respect to the first cam;
The variable valve operating apparatus for an internal combustion engine, wherein the cam surface of the second cam is formed with a cam width dimension larger than a cam width of the cam surface of the first cam. The shaft member is configured such that an inner cam shaft is rotatably accommodated in an outer cam shaft formed of a pipe member,
The first cam is provided on an outer peripheral portion of the outer cam shaft, and the second cam is provided so as to be rotatable around an axis of the outer cam shaft,
2. The structure according to claim 1, wherein the phase of the second cam is variable with respect to the first cam by relative displacement between the outer cam shaft and the inner cam shaft. The variable valve operating apparatus for an internal combustion engine. A camshaft applied to an internal combustion engine of the same model as the internal combustion engine, wherein the camshaft includes a cam integral with a shaft member, the first cam is larger than the cam width of the cam of the camshaft. The variable valve operating apparatus for an internal combustion engine according to claim 1 or 2, wherein the cam width of the internal combustion engine is formed with a large dimension.

Images